Small cosmetic wind adjustments

[weluvgoatz]

This PR makes the wind particles point in the proper direction now, as well as putting wind on a layer behind others so that you can actually grab other objects in the editor when there's wind in the level.

[tobbi]

This will fail if sprite ever is NULL (null dereference).

[tobbi]

@mrkubax10 Were you so certain that sprite could never be null that you deref'ed it without checking?

[mrkubax10]

If you return a pointer instead it will fail in other place.

[tobbi]

Not when there's suitable null checks.

[weluvgoatz]

Closing as there doesn't seem to be any desire to have this.